﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    class Subtract:Calculate
    {
        double sum;
        public void subtract()
        {
            sum = first - second;
        }
        public override void DisplayResult()
        {
            base.DisplayResult();
            Console.WriteLine("结果为:"+sum);
        }
    }
}
